/Engine/Plugins/Online/OnlineSubsystem/Source/Public/Interfaces/OnlinePartyInterface.h
Query a party to check it's current joinability Intended to be used before a call to LeaveParty (to leave your existing party, which would then be followed by JoinParty) Note that the party's joinability can change from moment to moment so a successful response for this does not guarantee a successful JoinParty
void QueryPartyJoinability ( const [FUniqueNetId](API\Runtime\CoreOnline\Online\FUniqueNetId) & LocalUserId, const [IOnlinePartyJoinInfo](API\Plugins\OnlineSubsystem\Interfaces\IOnlinePartyJoinInfo) & OnlinePartyJoinInfo, const [FOnQueryPartyJoinabilityCompleteEx](API\Plugins\OnlineSubsystem\Interfaces\FOnQueryPartyJoinabilityComplete-) & Delegate )